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The prenyl-binding protein PrBP/δ is a solubilization factor involved in trafficking of prenylated proteins. Here the authors present the ligand-free apo-PrBP/δ structure and propose a "solubilization by depletion" mechanism, where PrBP/δ sequesters only soluble rod photoreceptor phosphodiesterase (PDE6), leading to a dissociation of membrane-bound PDE6.

Resilience is a functional attribute of shield tunnels to ensure continued serviceability. From the performance-based perspective, the concept of deformational resilience is proposed and defined as the ability to resist deformation development (robustness) and the ability to recover from pre-existing deformation (recoverability). This work aims to measure the deformational resilience of shield tunnel lining structure, targeting at its most vulnerable part—longitudinal joint. For this purpose, a series of full-scale tests are carried out to perform 1) the failure process to simulate external surcharge loads, 2) the recovery process to simulate the effects of unloading and tunnel bilateral soil grouting, and 3) the cyclic loading process to simulate incremental cycling loading and unloading conditions. The assessment of deformational resilience is based on joint opening from the tests and related structural energy analysis. The test results demonstrate that the capability of tunnel longitudinal joint to resist deformation deteriorates with increasing overload level, and the recovery efficiency of joint opening presents nonlinear degradation with the increase of pre-existing deformation. The deformational resilience of longitudinal joint revealed in this research can facilitate the selection of appropriate timing and optimal design of technical parameters related to recovery measures for over-deformed shield tunnels. [ABSTRACT FROM AUTHOR]

An exact solution of steady state, electroosmotic, transient magnetohydrodynamic (MHD) flow, and heat transfer of a viscous and incompressible electrically conducting nanofluid consists of water and Cu metal, through a microparallel channel under the combined effect of pressure and vertically acting magnetic field is found. An exact solution is calculated through Laplace transform using the software of Mathematica to find the steady velocity and temperature field depending on many dimensionless parameters. The electromagnetic couple effect, the volumetric generation of heat caused by the Joule heating effect, and viscous dissipation are considered to analyze the thermally fully formed heat flow problem based on the steady part of the velocity field. The exact result of the temperature field is obtained by taking the uniform boundary heat flux. The significant parameter of heat flow known as the Nusselt number, depending on the height of the microtube, is defined. At last, the entropy generation of MHD temperature flow is analyzed. The interpretation of variations that occurred in internal and external entropy generations is given and consequences are explained. [ABSTRACT FROM AUTHOR]

This paper provides direct evidence of attempted tax evasion in response to changes in tariff rates in a small open economy using transaction‐level customs data for Pakistani importers. Our results show that there exists a systematic relationship between the difference in declared and assessed import values of the shipment, and the duty rate charged to the importer. We demonstrate that higher duty rates are associated with a greater misdeclaration of imports. In particular, a one‐percentage point increase in duty rates, on average, is linked with 0.4% increase in under‐invoicing of imports by Pakistani firms. The study explores several dimensions to examine the variation in estimates obtained across product types, import origins, modes of processing import transactions and the role of firm characteristics, such as, frequency of imports, in determining the extent of misdeclaration. [ABSTRACT FROM AUTHOR]

In this study, three-dimensional upper-convected Maxwell fluid flow over a stretching surface in the presence of viscous dissipation and Joule heating is considered to examine the effects of thermophoresis and magnetohydrodynamics (MHD) on heat and mass transfer. Energy equation is formulated under the assumption of nonlinear radiative heat flux. Ordinary differential equations are deduced from the governing partial differential equations with the help of similarity transformation. These equations are then solved numerically using the shooting method, through the fourth-order Runge-Kutta integration procedure. To strengthen the reliability of our results, the MATLAB built-in function bvp4c is also used. Effects of some prominent physical parameters, such as Eckert number, Prandtl number, thermophoretic parameter, and magnetic parameter on the velocity, temperature, and concentration profiles are discussed graphically and numerically. It is found that concentration profile decreases for the higher values of thermophoretic parameter and Schmidt number. The heat flux rate is observed to enhance for increasing values of thermal radiation and Prandtl number. Key words: upper-convected Maxwell fluid, Joule heating, viscous dissipation, thermophoretic effect, magnetohydrodynamics, nonlinear thermal radiation. Nous considerons ici l'ecoulement d'un fluide de Maxwell convecte superieur sur une surface en etirement en presence de dissipation visqueuse et de chauffage par effet Joule, afin d'examiner les effets de la thermophorese et de la magnetohydrodynamique (MHD) sur le transfert de chaleur et de masse. L'equation d'energie s'ecrit sous l'hypothese d'un flux de chaleur radiatif non lineaire. Les equations directrices aux derivees partielles deviennent des equations differentielles ordinaires suite a une transformation de similarite et nous les solutionnons numeriquement par methode de Runge-Kutta du quatrieme ordre. Pour nous assurer de la fiabilite de nos resultats, nous utilisons aussi la fonction bvp4c de MATLAB. Nous analysons numeriquement et graphiquement l'effet de certains parametres importants, comme le nombre d'Eckert, le nombre de Prandtl, le parametre de thermophorese, le parametre magnetique sur la vitesse, la temperature et les profils de concentration. Nous trouvons que le profil de concentration diminue aux plus hautes valeurs du parametre de thermophorese et du nombre de Schmidt. Le taux de flux de chaleur croit avec l'augmentation de la radiation thermique et du nombre de Prandtl. [Traduit par la Redaction] Mots-cles: fluide de Maxwell convecte superieur, chauffage par effet Joule, dissipation visqueuse, magnetohydrodynamique, radiation thermique non lineaire., 1. Introduction Thermophoresis is a process in which fluid particles move towards a cooler region from a warmer region [1]. This movement occurs because molecules from the warmer region, having [...]

Purpose: To assess the effects of adhesive resin cement, obturation material and dentin location on the retention of glass fiber-reinforced resin composite (FRRC) posts. Methods: 60 root canals in single rooted teeth were obturated with three different protocols (n= 20), including no obturation material (Control), GuttaFlow and Gutta-percha. Spaces were prepared for glass (FRCR) posts. Subgroups of the roots (n=10) were allocated for receiving posts luted with RelyX Unicem or Calibra resin cements. The specimens were mounted in plastic molds using epoxy resin. They were sectioned transversely to obtain three 1 mm-thick coronal, middle and apical slabs. Post retention was measured using a universal testing machine. The push-out test was performed at a crosshead speed of 0.5 mm/minute until post dislodgement occurred. Dislodged posts were examined microscopically to evaluate the mode of failure. Data were analyzed using univariate tests to reveal the effects of dependent variables and their interactions on post retention. Tukey test was used to determine significant differences for post retention in obturation material and dentin location groups. P-values ≤ 0.05 were considered significant. Results: The adhesive resin cement, obturation material, dentin location and cement obturation materials interaction affected post retention. The mean bond strength was higher for posts cemented with RelyX Unicem than for those cemented with Calibra resin cements. Post retention in coronal locations was significantly superior to middle or apical locations. The failure mode was primarily mixed. [ABSTRACT FROM AUTHOR]

Severe and very severe hypertriglyceridemia although rare within the pediatric population occur more often among oncology patients, secondary to chemotherapeutic agents. Currently there exists minimal literature to guide management of severe hypertriglyceridemia among pediatric patients. Very-low-fat dietary restriction should be considered over nil per os (NPO) for initial management of severe hypertriglyceridemia in stable pediatric patients. Pediatricians caring for oncology patients must consider chylomicronemia as a potential etiology for presenting symptoms. Pediatric severe hypertriglyceridemia management guidelines are needed as pediatricians must currently rely on anecdotal experiences for management decisions. Three children receiving treatment for acute lymphoblastic leukemia required hospitalization for very severe hypertriglyceridemia. Management varied among the cases but included: NPO or very-low-fat diet, insulin, intravenous fluids, fibrates, and omega-3 fatty acids. These cases suggest that pediatric severe hypertriglyceridemia management, in the absence of pancreatitis should allow a very-low-fat diet initially rather than NPO followed by pharmacologic therapies. [ABSTRACT FROM AUTHOR]